A capturing instrument for maintaining a horizontal posture (hereinafter, referred to as a gimbal) according to the conventional technique has been designed in general to support a two-axis adjustment and a 3-axis adjustment. The number of driving units is determined depending on the number of adjustment axes. A vertical Z-axis rotation may be defined as yawing. An X-axis adjustment may be defined as pitching. A Y-axis adjustment may be defined as rolling.
Each axis has a driving unit which operates to maintain a horizontal posture. In each step, a rotation axis is associated with a next axial rotation. When the Z-axis rotates, driving units and constructions of the X- and Y-axes also rotate at the same time. When the Y-axis rotates, a construction of the X-axis rotates together. The X-axis is configured such that only constructions related to the X-axis rotate.
In the conventional technique, an additional camera is designed to be mounted to a gimbal, and the camera is fixedly mounted to an end of the X-axis which is a last rotation axis.
A gimbal to be mounted to a large camera may have an axis support at both ends thereof. However, a gimbal for a small camera uses a portion in which a driving unit exists as a rotation axis.
According to the conventional technique, a brushless motor is used in general as a driving unit, and is precisely controlled by a controller.